Uranium Powder is a brewing object used to make X-Ray Potion. It is also a brewing stand fuel for up to 15 brewing operations. Good subsitute for blaze powder. If it surrounds a nether portal, Zombie Pigmen or Ghasts (for larger portals) cannot spawn in the portal anymore. It has a luminosity of 8 when placed. Running on top of it can give you Hunger in Normal and Hunger II in Hard or Hardcore Mode. In Easy or Peaceful difficulty, running over it is safe.
How to Make
U=Uranium Ingot, GL=Glowstone Dust, R=Redstone Dust, G=Grass
The recipe gives you 5 uranium powder. Placing it makes a hostile mob deterrent.